Lens-measure.



W. GOWLLAND.

LENS MEASURE.

APPLICATION FILED DEC. 14, 1912.

1,136,419.- Patented Apr. 2o, 1915.

V/'ILLIAM GOWLLAND, 0F KEMP TOWN, ENGLAND.

LENS-MEASURE.

Specicaton of Letters Patent.

Patented Apr. 20, 1915.

Application filed December 14, 1912. Serial No. 736,858.

To all whom it may concern Beit known that I, WILLIAM GOWLLAND, subject of George V, King of Great Britain and Ireland, and residing at 30 Abbey road, Kemp Town, in the county of Sussex, England, have invented certain new and useful Improvements in Lens-Measures, of which the following is a specification.

Lensr measures have been already constructed which measure the curvatures of lenses by pressing three points, or a contact ring and a central point, against their surfaces, the central point or piston actuating a hand that registers the curvature on a dial. Such lens measures, however, are very complicated in construction and expensive, and having a large number of working parts, soon wear and register incorrectly. Also, these different lens measures being made with a case like that of a watch and with a separate plate for the movement or works, and also a separate piece for the extension piece that carries the three points, or the contact ring and point, there is always a source of wealmess and error in the different joints as well as expense and diiculty in manufacture. v

Now the object of the present invention is to provide an improved lens measure of the type mentioned and for the purpose stated which shall register with accuracy every lens for which it is constructed and of such a design that it can be manufactured easily and cheaply and without the defects mentioned above.

Figure l is a plan of the case and Fig. 1a is a mid-section thereof. Figs. 2 and 2a are similar views respectively of a case and dial plate, the parts L and S shown in Fig. 2a being omitted from Fig. 2. Fig. 3 is a midsection of a modified form of case. Fig. 4 is an incomplete plan showing the operating mechanism on an enlarged scale. Fig. 5 is an incomplete plan of the dial plate on an enlarged scale.

The invention consists chieliy of constructing the main portion of the case A and the extension piece M out of one piece of metal as shown in Figs. 1 and la. Secondly, of a simplified movement the bearings for which are formed by the case and dial plate, as shown in the sectional drawing in Fig. This simplified movement may be used either in the types of cases as shown in Figs. 1, 2 and 3 or in any type of case. The case and extension piece, which may be a casting, but 1s preferably a stamping embossed to shape in one piece, has a ridge embossed on the upper part at A Figs. l, la, 2 and 3 in the inner edge of which is located the dia-l plate andover the outer edge of which is fitted the bezel which carries the glass.

The position of the dial plate is accurately registered by means of the two lugs l?. P. Fig. l. These two lugs are formed by the embossing dies at the same time that the case is embossed to shape. The positions of the holes R, R, R, R, that are eventually to be drilled in the case, and also indicated at the same time by the embossing dies by small indentations in the metal.

Another way to make the case and to still adhere to the plan of having the main portion of case and extension piece made of one piece of metal, is to shape the case as above but to fasten a separate plate C Fig. 3 to form the back of the case.

The working parts consist of a pinion D Fig. 4 and hair spring B to which pinion the indicating hand (not shown) is attached, a segment rack E and `the usual piston Fl which presses against the lens. The segment rack E Fig. 4, which works on a bearing G, carried by and near the edge of the case, has an adjustable abutment or leg H against the curved end of which the flat inner end of the piston F abuts, so that when the piston F is pushed inward (while testing a lens) the segment rack E is partly revolved on its central bearing G and so turns the pinion D to which the indicating hand is attached, thus registering the curvature of the lens.

The piston has an enlarged portion f at its inner end which prevents it falling out of the instrument.

The end of the adjustable abutment or leg H is shaped with a true curve and the curve may be either a portion of a cylinder or a sphere.

The angular movement of the indicating hand over the dial corresponding to a given movement to the piston F may be varied by altering the distance of the abutment or leg H from the central bearing G to the segment rack E by means of the screw J. This adjustment provides a means of adjusting the instrument after it is assembled and also to suit the refractive index of the glass of which the lenses may be made. I prefer the curvature on the end of the adjustable leg H v to be a portion of as large a circleA or sphere adjustment and simply have the curved adjustment Hv in Contact With the flat end of the piston F.

Instead of having the usual back plate to form the bearing for one end' of the pinion, I use a hole partly drilled through the case as shown at IQFig. 2a. Also instead of the usual cocked piece or bearing for the top t end of pinion I use a hole drilled through ten the Contact ring to 'the endk ofthe eXtenthe dial plate S as shown at L Fig. 2. Irovision is vmade for adjusting the screw J afterthe instrument is assembled.

The graduations on the dialv are out right l vthrough the material as shown at Fig. 5 instead of being marked or engraved on its surface.

Referring to the type of case shown at Figs. 2 and 4f, the extension piece is soldered or fastened directly to the case instead of to the usual back plate that usually lits into the round sunk portion of it.

As regards the type of instrumentV that has a Contact ring and a central point I fassion pieoe.

I use any method ofV making the move- Vment in combination With my methods of making the cases as shown at Figs. 1, 2 and 31.A

I claim: Y Y Y 1. In a lens measure, a movable plunger, a case, a dial plate, a toothed segment adapted 'to be operated by the movable plunger, registering means geared to said toothed segment having a curved surface engaging the said plunger, and an adjustable leg on said toothed segment, substantially as described.

2. In a lens measure of the type in VWhich the registering means are operatedu by the aid ofV a movable plunger, acase, a dialplate, a toothedsegment, a bearing for said toothed segment, registering means geared-Y to said toothed segment, a leg forming part Aof said toothedsegment and provided With a curved surfaceforengagement with said Y plunger, and means for varying the position of'said leg relatively to said bearing.

3. In a lens measure of the type in Which the registering means are operated by theV aid of a movable plunger', a ease consisting of a main portion (A) 'and an extension (M) embossed or stamped up from a single piece'.

of metal, a dial-platehaving its graduations cut completely through it, a toothed segment, a bearing for said toothedsegment, a leg forming part of said toothed segment and provided'vvith a surface which is ofarc or spherical form `for engagement with said plunger, means for varying the position of said leg relatively to said bearing and regis` tering means geared to said toothed segment.

In Witness `whereof I have hereunto set my` hand inthe presence of two Witnesses.

` WILLIAM GOWLLAND. Witnesses:

H. T; PLACE, VoLTAs W. WORD.

G'opes oijthis patent may be obtained for -fwe cents each, by addressing the Commissioner of Patents,

Washington, D, GJ 

